Valves acceptable Factory Spec

Jose J Ortega

Registered
Hi, I am planning to check my valve clearance next week. Was reading the repair handbook and it says:

Acceptable Factory Exhaust Spec is .008 - .012" and Acceptable Factory Intake Spec is .004 -. 008"

My question between the spec for the exhaust: If you have to shim it, Will you use a shim closer to .008 or .012? Same question for the intake: Will you shim it closer to .004 or .008? Than you in advance
 
You get the range because you may not be able to get them all on the high or the low side of the range.
Shoot for the middle.
You may be able to move a couple shims from one valve to another, but you will need a shim kit.
You may even get lucky and find them all in spec, or be able to get by swapping some.
But, it usually never fails, and you'll end up needing a couple.
 
You get the range because you may not be able to get them all on the high or the low side of the range.
Shoot for the middle.
You may be able to move a couple shims from one valve to another, but you will need a shim kit.
You may even get lucky and find them all in spec, or be able to get by swapping some.
But, it usually never fails, and you'll end up needing a couple.

sixpack577 You are always on point brother. Thank you so much for all your help:thumbsup:
 
sixpack577 question: If I have to shim the valves. I already got that I have to remove the tensioner, remove the cams etc.. When I remove the chain tensioner. When I reassemble all back ( check timing, etc) Will the tensioner stay at the same position that was? or I have to reset the Chain tensioner?
 
Never mind... I found the answer. The tensioner has a middle bolt with a spring. When I reinstall it, I install the case first then the spring and the bolt. That will push the tensioner to the correct tension. :super:
 
I might take this opportunity to put an APE tensioner on there. My OEM CCT seems to be doing the job but a manual tensioner is safer for harsh use and you probably will never need to reset it after installing. $60. However, if the OEM is not hard to install, it does seem to work quite well. Never actually looked at how it works but a manual tensioner stays at the tension you set it all the time where a automatic probably has some play. Does the busa need this mod?
 
In progress:beerchug:

20180114_202158.jpg
 
looking at the Service manual Chart and it doesn't give me what will be new Valve clearance with the recommended shim. Trying to figure out how to calculate what will be the new valve clearance.

Maybe with this formula: ( correct me if I am wrong lol)
** This is just a example, I have not verify my Valve clearance yet**

. 250 old shim
.006 recorded Valve Clearance
Specify Clearance (on the lose side) that I want to take it to .012

The ticker the shim less clearance. Smallest the shim more clearance

If I am correct I will need a -.006 to get .012 of valve clearance

.250 old shim -.006 = New Shim 0.244
 
looking at the Service manual Chart and it doesn't give me what will be new Valve clearance with the recommended shim. Trying to figure out how to calculate what will be the new valve clearance.

Maybe with this formula: ( correct me if I am wrong lol)
** This is just a example, I have not verify my Valve clearance yet**

. 250 old shim
.006 recorded Valve Clearance
Specify Clearance (on the lose side) that I want to take it to .012

The ticker the shim less clearance. Smallest the shim more clearance

If I am correct I will need a -.006 to get .012 of valve clearance

.250 old shim -.006 = New Shim 0.244

Yes, that's right
 
I might take this opportunity to put an APE tensioner on there. My OEM CCT seems to be doing the job but a manual tensioner is safer for harsh use and you probably will never need to reset it after installing. $60. However, if the OEM is not hard to install, it does seem to work quite well. Never actually looked at how it works but a manual tensioner stays at the tension you set it all the time where a automatic probably has some play. Does the busa need this mod?

If you install a manual tensioner you Will need to adjust it, or at least check it.
The auto adjuster does like it sounds, automatically applies more tension as the chain gets slack from wear.
A manual is adjusted, manually, against the chain. So if you never adjust it, you never apply more pressure against the timing chain as it stretches and wears over time.
You Need to check a manual tensioner.
Never a bad idea to check an automatic one either, to make sure it's in spec.
 
A manual is adjusted, manually, against the chain. So if you never adjust it, you never apply more pressure against the timing chain as it stretches and wears over time. You Need to check a manual tensioner.

Makes sense however if the busa is like the ZX-14, the timing chain will rattle at idle when it gets loose and that's the signal that it's time to adjust the tensioner. My 14's OEM tensioner was rattling (common ZX-14 problem) so I changed to an APE tensioner and have not heard a rattle in about 25,000 miles. If busas don't seem to have this problem, I would be more confident they are keeping adequate tension at all times. A manual tensioner still might be a good race mod for a busa. I haven't heard of them being used on the busa like they often are on the 14.

I just did a quick search on here and it seems like in most cases, the OEM tensioner is recommended for all applications. The only time I see a manual tensioner recommended is when the OEM one gets noisy at idle like the 14's often does. They do also say to check a manual tensioner. I guess I better do that on my 14. It's not a difficult procedure. No disassembly required, just loosen the locknut and see if the chain rattles when you back the tensioner out a bit.
 
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If you install a manual tensioner you Will need to adjust it, or at least check it.
The auto adjuster does like it sounds, automatically applies more tension as the chain gets slack from wear.
A manual is adjusted, manually, against the chain. So if you never adjust it, you never apply more pressure against the timing chain as it stretches and wears over time.
You Need to check a manual tensioner.
Never a bad idea to check an automatic one either, to make sure it's in spec.

Any advice on adjusting a manual tensioner? When my tensioner became loose it made a rattling noise at 2k. I simply tightened the tensioner until the noise stopped. Does that sound about right? or should you give it an extra 1/8-1/4 turn?
 
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